Apparatus for carbonating lead oxid.



F. H. SHARPE.

APPARATUS FOR CARBONATING LEAD OXID.

APPLICATION FILED IAY3I, I9I6.

1,214,229. Patented A Jan. 30, 1917.

7 2 SHEETS-SHEET l- F. H. 'SHARPE. APPARATUS FOR CARBONATING LEAD OXID.

v APPLICATION FILED IAY3I. I915. I I 1,214,229. Patented Jan. 30, 1917.

2 SHEETS-SHEET 2- m'iewweisu Wnrzzex IN! nouns runs an. noomuum. vnnlndmn. n r.

UNITED STATES PATENT OFFICE.

rnnnnnrex HERBERT SHABPE, or LIVERPOOL, ENGLAND.

APPARATUS FOR CARBONATING LEAD'OXID;

Specification of Letters Patent.

Patented Jan. 30, 1917.

Original application filed July 12, 1915, Serial No. 39,448. Divided and this application filed May 31, 1918. Serial No. 100,991.

Letters Patent of the United States filed on the 12th July, 19l5,1Serial No. 39448, and is a division of that application.

The process of making white lead by pass ing carbon dioxid or a mixture of this gas with another gas or other gases through lead oxid suspended in water containing an assistant, such as a small proportionv of acetic acid, is well known. In carrying out the process, however, great d ifiicu'lty has been experienced in maintaining the solid and liquid in efficient contact with the gas,

with the result that a large proportion of the gas passes through the apparatus without being utilized. This arises in part from the high specific gravity of the lead oxid, which causes it to settle very quickly and in general the only way found practicable up to the present to meet the difiiculty has been to vigorously stir the mixture mechanically. This is, however, costly. Another solution of the difficult is that described in the specification o my prior United States Patent No. 1,088,460, inwhich as applied to the continuous manufacture ofwhite lead, a

"series of vessels is used through which the liquid with'its' suspended matter is passed consecutively and the gas is forced simply under pressure through the mixture in each vessel in turn. Experience with th1s process has shown that carbonation may vary in the difierent vessels and has suggested to the applicant that with a suitably constructed and arranged vessel the carbonation process mightbe carried out in one vessel and the mixture kept efficiently stirred without the use of any mechanical means for the purose. p Other main objects which I desire to accomplish by this invention are, to use ordicornmercial orv un-fiised lead oxid containing either free metallic lead or no metallic lead, which it has-been thouglzt impossi hletouse in .a single vat process ause of the metallic lead which has been left uncarbonated, to carbonate continuously, and to utilize carbonic acid gas of varying strengths.

The present invention to this end comprises apparat-us for the manufacture of white lead in a single vat, wherein lead oxid suspended in water containin an assistant is charged into the vat an carbon dioxid alone or mixed with another gas or other gases is introduced into the vat at or near the bottom in such a manner as to prevent settlement of the white lead and to cause thorough and efficient contact between the gas, the solid and the liquid.

The invention will be described with rel? erence to the accompanying drawings.

Figure 1 is a vertical section through a vat or carbonating lead oxid constructed according to the invention. Fig. 2 is a sec-. tion on line 2-2 of Fig. 1 drawn to an enlarged scale. Fig. 3 is i an elevation with part shown in section, illustrating another arrangement of. vat. Fig. 4: is asection on line 4-4 of Fig. 3. Fig. 5 is a detail view showing one'of the gas supply pipes disconnected. Fig. 6 is another detail view showing one of the jet cleanin plungers; Fig- 7 is a horizontal section: on fine 77 of Fig. 3 showing a baflle ring. Fig. 8 is a partial elevation on line 88 of Fig. 7. p

The" mixture of lead oxid, water. and a small proportion of acetic acid" is run into the vat a, which preferably tapers inwardly toward the bottom, through a cock 6. The carbonating gas which ma be substantially pure carbon dioxi-d or file gases, for exampie, is pumped through a pipe" 0, the delivery. end of which is provided with a bellmouthed extension at directed toward the spherically curved bottom of the vat and situated within a' short. distance thereof. Close to the said delivery end there project at right angles to the axis of the pipe four short curved horizontal pipes 6, also bell-. mouthed. The cross sectional areas of these four pipes at their junction with pipe 0 and the cross sectional .area of the extension d at its junction with the-pipe 0, are together preferably slightly lessthan the cross sectional area of pipe c, so as to insure that there shall always be an excess pressure in is removed through the test cock gree, cock 9 is opened, whereupon the pressure of gas in the vat expels the liquid and solid contents. Cock 9 is now closed and more mixture is pumped in through cock I), the stream of gas being continued the while, so that the process may. be said to be practically continuous.

The blow-off valve. k may be loaded to give any desired pressure within the vessel. lVorking under pressure is not essential, but has the advantage that it aids the intimate contact of the gas with the mixture and prevents the excessive frothing which would occur in an open vessel.

If the quantity of metallic lead in the oxid be abnormally large, air may be forced through a separateopening in the vat so as to insure the oxidation of this lead, which might otl'ierwise escape carbonation owing to insufficiency of the accidental oxygen in the carbonating gases.

Should apparatus such as that above described be allowed to standfor any reason, any lead oxid in the vat at once settles to the bottom and may have a tendency to choke the gas delivery jets d and e, in which case it is necessary to remove the pipe 0 and the jets to clean them, the apparatus at the same time being put out of use. The arrangement shown in Figs. 3 to 6 has been designed to obviate such a difficulty.

The vat a is preferably similar in shape to that shown in Fig. 1, that is to say it is constructed tapering inwardly toward the bottom so that the lower portion a of the vat is of more or less conical shape and the actual bottom is of the vat is preferably made of comparatively very small size and slightlydomed or conical, as shown, so as to throw anything falling on it down to the edges. At or near the bottom of the vat are arranged one or more jets 6 introduced through the walls of the vat and directedmore or less tangentially to said walls.

Preferably the direction isslightly more toward the center of the vat than the true tangential direction. The direction of the jets may also, if desired, be slightlydownward toward the bottom of the vat.

Whenone jet 6 is used the lower portion a of the vat may be carried more nearly to a point and the area of the jet may be made greater than the area of the actual bottom 2 of the vat. It is, however, preferable to employ a plurality of jets e as shown, because this means the agitation of the material is more readily produced and maintained and it is possible as hereinafter described to clean one jet while the others are continuously in operation. Each of the jets a is provided with a preferably full bore cock 1 adjacent to it, by which it can be shut off,

I, and when such a sample shows that the leadoxid has been carbonated to the desired deand with a removable connecting pipe m (see Fig. 5) removably attached beyond the cock Zby which it is connected with the main gas supply pipe or. A cock n is also provided between the main supply n and each of the pipes 722. so arranged that the gas can be shut off from each pipe m individually to permit of its being disconnected and removed without interfering with the supply to the other pipes. Each pipe m 1s preferably made in two sections as shown with a non-return valve m arranged between them, to prevent any back pressure in the vat forcing the material in the vat back into or along them.

Vhen itis desired to clean or inspect one of the jets c or its connecting pipe m, the cocks Z and a corresponding are closed and the pipe m is disconnected. It can then be inspected and cleaned, its two separate sections being disconnected from the non-rcturn valve 112. if found necessary. A plug is then inserted in the bore of the cock 7, the cock is opened and the plug is pushed into the vat to clean out the jet and then withdrawn, the cock Z being closed again, before the plug is finally removed. Or, as shown in the drawings (see especially Fig. 6) a plug 0, permanently arranged in a suitable recess in the pipe m and in line with the corresponding jet e may be provided for cleaning each jet. The plug 0 is preferably arranged as shown in a separate junction piece m and is provided with a handle 0' passing through a stufling box m by which it can be operated.

The vat is provided with a cock 9 by which the contents may be evacuated and may be provided with a second cock 1? at the bottom by which any sediment collected time.

In operation, after the vat has been filled and the gas has been turned on, a rapid vertical movement is set up in the vat owing to the direction of flow of the gasunder pressure through the jets. The gas at the same time tends to rise up the sides of the vat passing around and around then more or less in a helical direction. Atthe same time the oxid of lead which is thrown to the sides by the centrifugal action tends to fall so that it is brought into intimate contact with 7 the rising gas. A more or less general circulation of the liquid is also produced upward along the sides of the vat and downward in the more quiescent center of the vat.

In order to increase the agitation and prevent too regular a circulation of the liquid and also tomore efliciently use up the gas, one or more circular, preferably downwardly inclined baflles 1' (see Figs. 3, 7 and 8) may be arralged in the upper part ofthe vat. Such ba es 1' may extend almost around the vat leaving a narrow s between the Cir ends which is covered over with an angle plate tprojecting outward toward the center of the vat. Such baflles trap a portion of the rising gas which is led through the space 5 and the gable t toward the center of the vat and rises against the downwardly circulating liquid.

One or more test cocks f are provided in the side of the vat. When the carbonation is completed, the cock 9 is opened, the contents being forced out by this cock under the pressure of gas in the vat, the gas inlet valves being left open while the vat is evacuated. Directly the vat is emptied the cock 9 is closed and the new material is fed into the vat without shutting oh" the gas supply. In this Way, agitation and carbonation of the new material as it is added begins immediately so that carbonation is continuous and no time being allowed for standing no settlement can take place in the vat. A blowoff valve in for regulating the pressure in the vat may be employed with reference to Figs. 1 and 2.

The gas passing from the vat may be allowed to escape to the atmosphere, or if of sufficient strength it may be passed through a second vat, but when this is done there is no other connection between the vats, the

complete process of carbonation taking place in a single vat.

Having thus described my invention and the best means I know for carrying the same into practical effect, I claim 1. Apparatus for the manufacture of white lead, comprising a va-t adapted to receive the substances to be treated, and means for inducing in the lower portion of the vat a flow of an agitating agent in a substantially helical course upwardly to prevent settlement of solid material and cause thorough and eliieient contact between the substances under treatment.

2. Apparatus for the manufacture of white lead, comprising a vat to receive the substances to be treated, the vat having an inverted substantially conical side wall, and a jet for introducing an agitating fluid in a direction approximately tangential to the conical side Wall of the vat, said conical wall and the jet cooperating to induce a helical flow of the agitating fluid.

Apparatus for the mainlfacturc of white lead, comprising a vat having a substantially conical side and adapted to contain the substances to he treated, and a plurality oi. jets all having a pitch in the same direction for introducing an agitating gas in directions approximately tangential to the conical side of the vat and to coact with the side of the vat to induce a helical flow of the substances under treatment.

a. A PPQ ratus for the manufacture of white lead, .4. omPrm'og a vat adapted to receive the substances to be treated, the lower portion of the vat being of inverted conical shape, and means for introducingan agitating gas into the lower portion of the vat in a direction substantially tangential to that portion of the vat which is of inverted conical shape, said conical portion of the vat and the means for introducing the agitating gas cooperating to induce a helical flow of the agitating gas and the substances under treatment.

The combination with apparatus for the manufacture of white lead, embodying a plurality of jets through which an agitating agent is delivered into a vat, of removable connecting pipes connecting the separate jets to the main gas supply so that each jet and its connections can be cleaned without stopping the others.

6. In apparatus for the manufacture of white lead, embodying a plurality of jets through which an agitating agent is delivered into a vat, the combination with each jet of a cleaning plug adapted to be pushed through the jet to clear it of sediment.

7. In an apparatus for the manufacture of white lead, a vat to receive the substances to he treated, means for introducing an agitating gas into the lower portion of the vat, an annular bafile arranged around the sides of the vat for collecting a portion of the rising agitating gas and a part projecting inwardly from the bailie to deflect the gas so collected toward the center of the vat.

In testimony whereof I have signed my name to this specification in the presence of Copies 01' this patent may be obtained for five cents each, by addressing the Commissioner 0! Patents,

Washington, D. C. 

